Investigation of the interactions of incremental surface layer forming and HPPMS coating on fine blanking dies in order to enable a load-applied surface integrity adjustment (TEStOI)

在通过精冲加工高强度金属板材以生产汽车工业中的制动片托架等功能部件时，与传统金属板材相比，工具负载增加。用于机械表面层成形的增量方法，例如深滚，适合于通过增加耐磨性来增加工具寿命。机械表面处理用于改善动态负载部件的表面完整性（OI）。氧指数包括刀具表面层的显微组织、硬度分布、残余应力、表面形貌和损伤。为了进一步减少磨损和粘着磨损，工具的功能表面通过物理气相沉积（PVD）进行涂层。使用基于知识的工艺设计，可以选择性地影响涂层的OI。此外，涂层的特定OI对工具表面层的OI和化合物粘附具有积极影响。特别地，工具表面层的残余应力和微观结构可以通过涂层沉积期间的热应力以及在精冲过程期间的表面层的循环弹性机械应力而连续地松弛。关于OI的热稳定性和弹性稳定性的相应物理因果关系大多未知。一方面，目前还不清楚涂层过程中的热输入如何改变工具的OI，以及涂层的OI和工具中逐渐设定的OI之间发生了什么样的相互作用。另一方面，它是未知的，如何在冲裁过程中的循环弹性机械载荷影响的工具表面层的OI。因此，该项目基于研究假设，即通过增量表面层转变和PVD涂层设置的OI可以设计为在摩擦引起的热载荷和随后的循环机械载荷下，在基材温度T < 300 °C的低温涂层工艺中保持稳定。研究了刀具表面涂层氧指数的热稳定性和弹性稳定性以及PVD涂层氧指数的影响。一方面，专门调整工具表面层的OI，然后通过高性能等离子体工艺对工具表面进行涂覆。另一方面，工具表面层和涂层的调查进行，以分析生产工艺的影响，并得出一个合适的组合的工艺参数。为了扩大调查结果，在数值模拟中检查OI的行为。

In the processing of high-strength sheet metal materials for the production of functional components such as brake pad carriers in the automotive industry by means of fine blanking the tool load increases compared to conventional sheet metal materials. Incremental methods for the mechanical surface layer forming, such as deep rolling, are suitable for increasing the tool lifetime by increasing the wear resistance. Mechanical surface treatment is used to improve the surface integrity (OI) of dynamically loaded parts. The OI includes microstructure, hardness profile, residual stresses, surface topography and damage of the tool surface layer. In order to further reduce abrasive and adhesive wear, the functional surfaces of the tools are coated by means of physical vapour deposition (PVD). Using a knowledge-based process design, it is possible to influence the OI of the coating selectively. A specific OI of the coating furthermore has a positive effect on the OI of the tool surface layer and the compound adhesion. In particular, the residual stress and the microstructure of the tool surface layer, however, can be successively relaxed by the thermal stress during the coating deposition as well as under cyclic elasto-mechanical stress of the surface layer during the fine blanking process. The corresponding physical cause-effect relationships with regard to the thermal and elastic stability of the OI are mostly unknown. On the one hand, it is unclear how the heat input during the coating process alters the OI of the tool and what interactions occur between the OI of the coating and the incrementally set OI in the tool. On the other hand, it is unknown how the cyclic elasto-mechanical load during the blanking process affects the OI of the tool surface layer. Therefore, the project is based on the research hypothesis that the OI which has been set by means of incremental surface layer transformation and PVD coating can be designed to be stable in a low-temperature coating process at substrate temperatures T < 300 °C under a friction-induced thermal and subsequent cyclic mechanical load. The thermal and elastic stability of the OI of the tool surface layer as well as the influence of the OI of the PVD coatings are investigated. On the one hand, the OI of the tool surface layer is specifically adjusted and then the tool surface is coated by means of a high-performance plasma process. On the other hand, investigations of the tool surface layer and coatings are carried out in order to analyze the influences of the production processes and to derive a suitable combination of process parameters. In order to expand the findings, the behaviour of the OI is examined in a numerical simulation.